> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/analytics/mariadb-columnstore/reference/columnstore-naming-conventions.md).

# ColumnStore Naming Conventions

## Overview

This lists the different naming conventions enforced by the column store, compared to the normal [MariaDB naming conventions](/docs/server/reference/sql-structure/sql-language-structure/identifier-names.md).

* Usernames: 64 characters (MariaDB has 80)
* Table and column names are restricted to alphanumeric and underscore only, i.e. "A-Z a-z 0-9 \_".
* The first character of all table and column names should be an `ASCII` letter (a-z A-Z).
* ColumnStore reserves certain words that MariaDB does not, such as `SELECT`, `CHAR` and `TABLE`, so even wrapped in backticks these cannot be used.

## Reserved Words

In addition to MariaDB Server [reserved words](/docs/server/reference/sql-structure/sql-language-structure/reserved-words.md), ColumnStore has additional reserved words that cannot be used as table names, column names or user defined variables, functions or stored procedure names.

| Keyword         |
| --------------- |
| ACTION          |
| ADD             |
| ALTER           |
| AUTO\_INCREMENT |
| BIGINT          |
| BIT             |
| CASCADE         |
| CHANGE          |
| CHARACTER       |
| CHARSET         |
| CHECK           |
| CLOB            |
| COLUMN          |
| COLUMNS         |
| COMMENT         |
| CONSTRAINT      |
| CONSTRAINTS     |
| CREATE          |
| CURRENT\_USER   |
| DATETIME        |
| DEC             |
| DECIMAL         |
| DEFERRED        |
| DEFAULT         |
| DEFERRABLE      |
| DOUBLE          |
| DROP            |
| ENGINE          |
| EXISTS          |
| FOREIGN         |
| FULL            |
| IDB\_BLOB       |
| IDB\_CHAR       |
| IDB\_DELETE     |
| IDB\_FLOAT      |
| IDB\_INT        |
| IF              |
| IMMEDIATE       |
| INDEX           |
| INITIALLY       |
| INTEGER         |
| KEY             |
| MATCH           |
| MAX\_ROWS       |
| MIN\_ROWS       |
| MODIFY          |
| NO              |
| NOT             |
| NULL\_TOK       |
| NUMBER          |
| NUMERIC         |
| ON              |
| PARTIAL         |
| PRECISION       |
| PRIMARY         |
| REAL            |
| REFERENCES      |
| RENAME          |
| RESTRICT        |
| SESSION\_USER   |
| SET             |
| SMALLINT        |
| SYSTEM\_USER    |
| TABLE           |
| TIME            |
| TINYINT         |
| TO              |
| TRUNCATE        |
| UNIQUE          |
| UNSIGNED        |
| UPDATE          |
| USER            |
| VARBINARY       |
| VARCHAR         |
| VARYING         |
| WITH            |
| ZONE            |

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